Propeller assembly and pitch control unit

Patent metadata

Field	Value
Publication number	US-11873771-B2
Application number	US-202218061852-A
Country	US
Kind code	B2
Filing date	Dec 5, 2022
Priority date	Jul 4, 2019
Publication date	Jan 16, 2024
Grant date	Jan 16, 2024

Abstract

A variable pitch propeller assembly operatively coupled with an engine and methods for controlling the pitch of a plurality of propeller blades thereof is provided. In one example aspect, the variable pitch propeller assembly includes features for combining overspeed, feathering, and reverse functionality in a single secondary control valve. The secondary control valve is operable to selectively allow a controlled amount of hydraulic fluid to flow to or from a pitch actuation assembly such that the pitch of the propeller blades can be adjusted to operate the variable pitch propeller assembly in one of a constant speed mode, a feather mode, and a reverse mode.

First claim

What is claimed is:

1. A propeller controller comprising:
at least one electrohydraulic servovalve operable to selectively allow a flow of hydraulic fluid to or from a propeller dome; and
at least one valve selectively fluidly coupling the propeller dome to an inlet port of the at least one electrohydraulic servovalve, wherein the at least one valve includes a one-way valve having an inlet fluidly coupled to the propeller dome and an outlet fluidly coupled to the inlet port of the at least one electrohydraulic servovalve and, the one-way valve having an open position and a closed position, the one-way valve in the open position supply hydraulic fluid from the propeller dome to the inlet port of the at least one electrohydraulic servovalve at a first hydraulic pressure at the inlet port, the one-way valve in the closed position to not supply hydraulic fluid from the propeller dome to the inlet port of the at least one electrohydraulic servovalve at a second hydraulic pressure at the inlet port, the first hydraulic pressure less than the second hydraulic pressure.

2. The propeller controller of claim 1 , further including a plurality of propeller blades rotatable about an axial direction and spaced apart along a circumferential direction, each propeller blade of the plurality of propeller blades rotatable through a plurality of blade angles about respective pitch axes each extending in a radial direction.

3. The propeller controller of claim 2 , further including a pitch actuation assembly for adjusting the plurality of propeller blades through the plurality of blade angles and including the propeller dome, the propeller dome defining a chamber.

4. The propeller controller of claim 2 , wherein the plurality of propeller blades move to a feather mode during an oil starvation condition at a lower speed than without the at least one valve.

5. The propeller controller of claim 1 , wherein the at least one electrohydraulic servovalve is a primary pitch control valve having a first stage and a second stage and the one- way valve is selectively fluidly coupled with the first stage.

6. The propeller controller of claim 1 , wherein the at least one electrohydraulic servovalve comprises a primary control valve operable to selectively allow the flow of hydraulic fluid to or from a pitch actuation assembly and a secondary control valve adjustable between a constant speed mode, a feather mode, and a reverse mode and operable to selectively allow the flow of hydraulic fluid to or from the pitch actuation assembly based at least in part on the mode of the secondary control valve.

7. The propeller controller of claim 6 , wherein the secondary control valve includes a valve body defining a chamber and a spool movable within the chamber and where the spool defines a first groove and a second groove, and wherein the primary control valve is fluidly connected with the first groove when the spool is in at least one constant speed position or in at least one reverse position.

8. The propeller controller of claim 6 , further including a pitch actuation assembly including:
a control piston translatable within the propeller dome;
a piston rod connected to the control piston and extending into a propeller gear box of an engine, the piston rod translatable in unison with the control piston;
an oil transfer bearing surrounding the piston rod within the propeller gear box of the engine and defining a flight gallery fluidly connected with the secondary control valve and a ground gallery fluidly connected with the secondary control valve; and
a beta tube enclosed within the piston rod and fluidly connecting the flight gallery with a chamber of the propeller dome.

9. The propeller controller of claim 8 , wherein a flight gallery conduit fluidly connects the secondary control valve with the flight gallery and a ground gallery conduit fluidly connects the secondary control valve with the ground gallery.

10. A method for controlling a variable pitch propeller assembly driven by a powerplant, the method comprising:
operating the powerplant;
controlling, using a controller, a first electrohydraulic servovalve adjustable between a constant speed mode, a feather mode, and a reverse mode to selectively allow a controlled amount of hydraulic fluid to or from a pitch actuation assembly of the variable pitch propeller assembly; and
selectively diverting, during an oil starvation condition, hydraulic fluid from a propeller dome of the variable pitch propeller assembly via a one-way valve, the one-way valve having an inlet fluidly coupled to the propeller dome and an outlet fluidly coupled to an inlet port of a second electrohydraulic servovalve and, wherein, during an oil starvation condition, the one-way valve in an open position to supply hydraulic fluid from the propeller dome to the inlet port of the second electrohydraulic servovalve, when an oil starvation condition is not present, the one-way valve in a closed position to not supply hydraulic fluid from the propeller dome to the inlet port of the second electrohydraulic servovalve.

11. The method of claim 10 , further including controlling a feathering with the second electrohydraulic servovalve upon a failure of the first electrohydraulic servovalve.

12. The method of claim 10 , wherein selectively diverting the hydraulic fluid from the propeller dome further includes opening a valve on a drain line to create a feather condition.

Assignees

• Ge Aviation Czech S R O
• Ge Avio Srl

Inventors

• Cervelli Giuseppe
• Castellani Simone
• Manzoni Miriam
• Bellocchio Giuseppe
• Jirasek Vojtech

Classifications

• F02D29/02 Primary

  peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers · CPC title

• B64C11/385

  comprising feathering, braking or stopping systems · CPC title

• B64C11/40

  automatic · CPC title

• B63H3/10

  characterised by having pitch control conjoint with propulsion plant control · CPC title

• F02B61/045

  for marine engines · CPC title